Alignable Connector

ABSTRACT

Connections between drill pipe sections and drill bits used for boring into the earth may comprise two elements threadably attachable one to another. A first element may comprise a rotor rotatable with respect to a stator. A second element may thread to the stator. As it does so, the second element may rotationally fix itself to the rotor allowing for connecting elements on the second element and the rotor to align. These connecting elements may remain aligned while the second element and rotor rotate with respect to the stator. Such alignment may allow for a connection to be kept clean and free from contamination in otherwise wet and dirty environments.

BACKGROUND

When exploring for or extracting subterranean resources such as oil, gas, or geothermal energy, it is common to form boreholes in the earth. Such boreholes are often formed by suspending a specialized drill bit from a derrick or offshore platform and rotating the drill bit to engage and degrade the earth as it turns. The drill bit may be suspended by coiled tubing or a series of drill pipe sections connected end-to-end forming a drill string, and rotated at the derrick/platform or by a downhole motor disposed towards an end of the drill string.

In many situations, it may be desirable to pass power or commands down a drill string to control tools or other devices disposed along the drill string. Such commands may attempt to alter drilling parameters to increase a rate of penetration of the drill bit or to steer the drill bit towards an attractive destination. It may also be desirable to gather information about an earthen formation being drilled and pass it up a drill string to the surface or along the drill string to other tools or devices. To gather this information, various types of sensors have been placed along drill strings or on drill bits to collect data.

Transmitting power, commands or information along a drill string or to and from a drill bit may prove challenging. First, connections between drill pipe sections and drill bits are often made in wet and dirty environments where drilling mud and greases may be prevalent. Contamination of connections by such materials may lead to faulty and unreliable communication. To avoid contamination, some have turned to electrical stab connectors with wipers thereon to make electrical connections in these types of dirty environments. A typical stab connector may comprise an electrically conductive projection axially alignable with an electrically conductive receptacle. The projection may be inserted into and received by the receptacle when axially translated relative thereto such that an electrical connection is made. To hinder drilling mud or grease from contaminating the connection, a wiper may be positioned at a mouth of the receptacle to wipe possible contaminates from the projection as it is inserted. Such a stab connector may not work properly, however, if the projection and receptacle are not continuously aligned. Second, it is common for drill pipe sections and drill bits to be threaded together. Such threaded rotational connections may make keeping a stab connector aligned difficult.

BRIEF DESCRIPTION

A connection between drill pipe sections or a drill bit may maintain alignment while two elements are threadably attached one to another. Such a connection may comprise a first element comprising a rotor rotatable with respect to a stator. A second element may thread to the stator. As it does so, the second element may rotationally fix itself to the rotor allowing for connecting elements on the second element and the rotor to align. These connecting elements may remain aligned while the second element and rotor rotate with respect to the stator. Such alignment may allow for a connection to be kept clean and free from contamination in otherwise wet and dirty environments.

DRAWINGS

FIG. 1 is an orthogonal view of an embodiment of a drilling operation comprising a drill bit secured to an end of a drill string suspended from a derrick.

FIG. 2 is a longitude-sectional view of an embodiment of drill bit, comprising a rotor rotatable with respect to a stator, positioned proximate an end of a drill string, threadably attachable to the stator and rotationally fixable with the rotor.

FIG. 3 is a longitude-sectional view of an embodiment of drill bit comprising a rotor with a pin extending therefrom received within a slot on an end of a drill string.

FIG. 4 is a perspective view of an embodiment of a drill bit disconnected from an end of a drill string.

FIG. 5 is a longitude-sectional view of an embodiment of drill pipe section, comprising a rotor rotatable with respect to a stator, positioned proximate another drill pipe section, threadably attachable to the stator and rotationally fixable with the rotor.

FIG. 6 is a perspective view of an embodiment of a drill bit, comprising a rotor with a plurality of crenellations disposed thereon, disconnected from an end of a drill string, comprising a plurality of mating crenellations disposed thereon.

FIGS. 7-1 and 7-2 are longitude-sectional views of an embodiment of a drill bit comprising a rotor with a slot disposed therein capable of receiving a pin extending from an end of a drill string, wherein a spring disposed adjacent the pin may absorb some force experienced by the pin.

FIGS. 8-1 and 8-2 are longitude-sectional views of an embodiment of a drill bit comprising a rotor rotationally fixable to an end of a drill string by a mule shoe connection.

FIG. 9 is a longitude-sectional view, including a magnified portion, of an embodiment of a drill bit comprising a rotor rotatable with respect to a stator and inductive rings capable of passing electrical signals during rotation.

FIG. 10 is a longitude-sectional view of an embodiment of a drill bit comprising a rotor rotatable with respect to a stator capable of passing optical signals during rotation.

FIG. 11 is a longitude-sectional view of an embodiment of a drill bit comprising a rotor rotatable with respect to a stator capable of passing fluid during rotation.

DETAILED DESCRIPTION

FIG. 1 shows an embodiment of a drilling operation comprising a drill bit 112 suspended from a derrick 113 by a drill string 114. The drill bit 112 may be rotated from the derrick 113 by a top drive, by a downhole motor disposed within the drill string 114, or by a combination of the two. As the drill bit 112 rotates it may engage and degrade an earthen formation 116 to form a borehole 111 therein. The drill bit 112 may be fed into the borehole 111 formed in the earthen formation 116 as the borehole 111 lengthens. Any of a variety of known downhole drill bits, such as a roller-cone bit or drag bit, may be used. Tools or other devices may be disposed at various locations along the drill string 114 to perform such tasks as controlling a rate of penetration of the drill bit or steering the drill bit towards an attractive destination. To gather information about the earthen formation 116 being drilled or the process of drilling as it progresses, any of a variety of sensors may be disposed along the drill string 114 or on the drill bit 112. While the present embodiment shows the drill string 114 suspended from a land based derrick 113, those of ordinary skill in the art will recognize that other configurations, such as suspending a drill string from an offshore platform are also possible.

FIG. 2 shows an embodiment of a drill bit 212 positioned proximate an end of a drill string 220. The drill bit 212 may comprise an internal component 221 residing within an external component 222. The external component 222 may comprise a working face 223 positioned opposite an opening 224. The working face 223 may comprise a plurality of cutters 299 comprising a superhard material (e.g. polycrystalline diamond) disposed on a series of blades 298 extending therefrom. The working face 223 may also comprise a plurality of nozzles 236 disposed thereon allowing for drilling fluid to discharge from the drill bit 212.

The opening 224 may provide for attachment of the drill bit 212 to the drill string 220. In the embodiment shown, the drill string 220 comprises a protrusion 225 extending from an end thereof with a first threaded surface 226 disposed on the protrusion 225. A second threaded surface 227 may be disposed on an internal surface within the opening 224 mateable with the first threaded surface 226.

The internal component 221 may be accessible through the opening 224. In the present embodiment, the internal component 221 is retained within the opening 224 by an insert 282 secured therein that retains the internal component 221 within the external component 222. An aperture disposed within the insert 282 may provide the internal surface comprising the second threaded surface 227.

The internal component 221 may comprise a pin 228 extending therefrom. The pin 228 may be received within a slot 229 disposed on the protrusion 225 as the first threaded surface 226 and second threaded surface 227 are mated together. In this manner, the protrusion 225 of the drill string 220 may engage with the internal component 221 such that the two rotate together with respect to the external component 222. While in the embodiment shown, a pin is disposed on an internal component and a slot is disposed on a protrusion, it should be understood that the reverse could be true with similar functionality. Further, other mechanisms could be employed to rotationally fix an internal component to a protrusion as threaded surfaces mate to achieve a similar effect.

One advantage of the elongated pin 228 and slot 229 shown in the present embodiment is that they may axially translate relative to each other for a considerable distance while the first and second threaded surfaces 226, 227 are threading together. Another advantage of an elongated pin 228 is that it may be longer than a stab connection aligned parallel with a rotational axis of the internal component 221. The stab connection may comprise an electrically conductive projection 280, disposed on the protrusion 225 and parallel with the pin 228, axially alignable with an electrically conductive receptacle 281, disposed on the internal component 221. By being longer than the stab connection, the pin 228 may align the projection 280 and receptacle 281 before stabbing.

FIG. 3 shows another embodiment of a drill bit 312 with a protrusion 325 completely threaded into an opening 324 thereof. When threaded, a projection 380 of a stab connection may be received by a receptacle 381. The stab connection may comprise at least one wiper 330 to clean possible contaminates from the stab connection during stabbing.

An external component 322 of the drill bit 312 may comprise a sensor 331 disposed thereon capable of measuring any of a variety of parameters of an earthen formation or a drilling operation as it progresses. The sensor 331 may be electrically connected to a first conductive ring 332 disposed on the external component 322. The first conductive ring 332 may be in physical contact with a second conductive ring 333 disposed on an internal component 321. As the internal component 321 and external component 322 may be rotatable with respect to one another, so to may the first conductive ring 332 and second conductive ring 333 be rotatable with respect to one another while maintaining contact. This physical contact may allow for an electrical connection between the sensor 331 and the receptacle 381, which may be in further electrical connection with the projection 380 through the stab connection. To maintain these electrical connections during rotation, it may be desirable to position the first and second conductive rings 332, 333 within a pressure vessel as shown.

In some embodiments, the internal component 321 may also comprise a passage 334 therethrough alignable with another passage 335 through the protrusion 325. These passages 334, 335 may allow for drilling fluid passing through a drill string to discharge through nozzles 336 within the external component 322 of the drill bit 312.

FIG. 4 shows another embodiment of a drill bit 412, this time, totally disconnected from an end of a drill string 420. Similar to previous embodiments, the drill bit 412 of this embodiment comprises an opening 424 with an internal component 421 accessible therein. The internal component 421 comprises a pin 428 that may engage with a slot 429 within a protrusion 425 of the drill string 420. Further, a plurality of projections 480 may be disposed generally equally spaced around a rotational axis of the protrusion 425 alignable with a plurality of receptacles 481 disposed generally equally spaced around a rotational axis of the internal component 421. In such an arrangement, each of the plurality of receptacles 481 may be connected to an individual conductive ring (not shown) to transmit power and/or data to or from each of a plurality of sensors 431 (only one shown).

FIG. 5 shows an embodiment of a first drill pipe section 512 positioned proximate a second drill pipe section 520. The first drill pipe section 512 may comprise a rotor 521 rotatable with respect to a stator 522. The second drill pipe section 520 may comprise a protrusion 525 extending from an end thereof with a first threaded surface 526 disposed thereon. The protrusion 525 may thread into a threaded box 524 disposed on the stator 522. As the protrusion 525 threads into the threaded box 524, a pin 528 extending from the rotor 521 may be received within a slot 529 disposed on the protrusion 525. The pin 528 and slot 529 combination may rotationally fix the rotor 521 to the protrusion 525. When rotationally fixed, a projection 580 of a stab connection may align and be received within a receptacle 581 to form an electrical connection. A first conductive ring 532 and a second conductive ring 533 may form an additional electrical connection between the rotor 521 and stator 522.

FIG. 6 shows an embodiment of a drill bit 612 comprising a rotor 621 with a plurality of crenellations 660 disposed thereon. A stator 622 of the drill bit 612 may be threaded onto a protrusion 625 extending from an end of a drill string 620. The protrusion 625 may comprise a plurality of mating crenellations 661 disposed thereon. The mating crenellations 661 of the protrusion 625 may mate with the crenellations 660 of the rotor 621 to rotationally fix the rotor 621 to the protrusion 625. While mated, projections 680 disposed on the protrusion 625 may be received within receptacles 681 disposed on the rotor 621 to form electrical connections.

FIGS. 7-1 and 7-2 show of an embodiment of a drill bit 712-1, 712-2 comprising a rotor 721-1, 721-2 with a slot 729-1, 729-2 disposed therein. A protrusion 725-1, 725-2 extending from an end of a drill string 720-1, 720-2 may comprise a pin 728-1, 728-2 receivable within the slot 729-1, 729-2 of the rotor 721-1, 721-2 as the drill bit 712-1, 712-2 is threaded onto the protrusion 725-1, 725-2. The protrusion 725-1, 725-2 may also comprise a spring 770-1, 770-2 disposed thereon adjacent the pin 728-1, 728-2. The spring 770-1, 770-2 may be capable of absorbing some of the force experienced by the pin 728-1, 728-2 before it finds its way into the slot 729-1, 729-2. For example, as the drill bit 712-1, 712-2 is threaded onto the protrusion 725-1, 725-2, the pin 728-1, 728-2 may rub against the rotor 721-1, 721-2 until it reaches the slot 729-1, 729-2 at which point it may insert itself therein. While rubbing against the rotor 721-1, 721-2, the spring 770-1, 770-2 may compress and absorb the force of the rubbing against the pin 728-1, 728-2 so as not to damage the pin 728-1, 728-2.

FIGS. 8-1 and 8-2 show an embodiment of a drill bit 812-1, 812-2 comprising a rotor 821-1, 821-2 rotationally fixable to a protrusion 825-1, 825-2 extending from an end of a drill string 820-1, 820-2. The rotor 821-1, 821-2 and protrusion 825-1, 825-2 may be rotationally fixable by a mule shoe connection. Specifically, the protrusion 825-1, 825-2 may comprise a hollow cylinder 880-1, 880-2 that may fit around a portion of the rotor 821-1, 821-2. The hollow cylinder 880-1, 880-2 may comprise a slit 881-1 disposed therein running along a length thereof. A projection 882-1, 882-2 may extend radially from the rotor 821-1, 821-2 that may fit into the slit 881-1 as the protrusion 825-1, 825-2 engages the rotor 821-1, 821-2. This projection 882-1, 882-2/slit 881-1 combination may rotationally fix the projection 882-1, 882-2 and rotor 821-1, 821-2 together while allowing them to translate axially relative to one another.

FIG. 9 shows an embodiment of a drill bit 912 comprising a rotor 921 rotatable with respect to a stator 922. In this embodiment, the rotor 921 comprises a first inductive ring 990 capable of passing electrical signals via a magnetic field to a second inductive ring 991 disposed on the stator 922. In such a configuration, electrical signals may be passed from the rotor 921 to the stator 922 while the two are rotating relative to each other while not requiring a physical connection between the two that could lead to wear. As can also be seen in this embodiment, the rotor 921 may comprise at least three inductive rings 990, 990-1, 990-2 each capable of passing a unique electrical signal. In this formation, multiple sensors 931 (only one visible) may be positioned around the drill bit 912 to take measurements from various locations and each transmit those measurements through individual inductive rings 990, 990-1, 990-2.

FIG. 10 shows an embodiment of a drill bit 1012 threadably attached to an end of a drill string 1020. The drill string 1020 may comprise a fiber optic cable 1010 passing therethrough capable of transmitting an optical signal, such as a laser, to the drill bit 1012. The drill bit 1012 may comprise a rotor 1021 rotatable with respect to a stator 1022. The rotor 1021 may comprise a reflective surface 1011 disposed thereon capable of directing the optical signal toward at least one sensor 1031 housed on the stator 1022. In this configuration, the optical signal may be transmitted to the sensor 1031 as the rotor 1021 rotates relative to the stator 1022. In other embodiments a reflective surface could be disposed on the stator with similar functionality.

FIG. 11 shows an embodiment of a drill bit 1112 connected to an end of a drill string 1120. In this embodiment, the drill bit 1112 takes the form of a roller-cone type bit while previous embodiments have comprised drag type bits. It should be understood that any variety of drill bit may be chosen. Fluid may travel along the drill string 1120 in a conduit 1110 capable of passing the fluid to the drill bit 1112. The drill bit 1112 may comprise a rotor 1121 rotatable with respect to a stator 1122. The rotor 1121 may comprise a first circular groove 1190 disposed thereabout adjacent a second circular groove 1191 disposed about the stator 1122. Fluid traveling along the drill string 1120 may fill the first circular groove 1190 and second circular groove 1191 allowing fluid to pass between the two as the rotor 1121 rotates relative to the stator 1122.

Whereas the present invention has been described in particular relation to the drawings attached hereto, it should be understood that other and further modifications apart from those shown or suggested herein, may be made within the scope and spirit of the present invention. 

1. An alignable connector, comprising: a first element comprising a rotor rotatable with respect to a stator; and a second element threadably attachable to the stator and rotationally fixable with the rotor.
 2. The alignable connector of claim 1, wherein the second element comprises a threaded pin, the stator comprises a threaded box, and the rotor is rotationally fixable by the threaded pin through the threaded box.
 3. The alignable connector of claim 1, wherein the second element comprises an elongate member with a channel capable of passing drilling fluid therethrough.
 4. The alignable connector of claim 3, wherein the rotor comprises a passage therethrough alignable with the channel in the second element.
 5. The alignable connector of claim 3, wherein the stator comprises a drill bit working face opposite an attachment end.
 6. The alignable connector of claim 5, wherein the stator further comprises a sensor disposed thereon connected to a rotatable connection formed between the stator and the rotor.
 7. The alignable connector of claim 1, wherein the second element is rotationally fixable with the rotor by a protrusion receivable within a slot, mateable crenellations, or a mule shoe connection.
 8. The alignable connector of claim 7, further comprising a spring disposed on the second element or rotor to absorb some force between the second element and rotor while they are becoming rotationally fixed.
 9. The alignable connector of claim 1, wherein the second element is axially translatable relative to the rotor while rotationally fixed.
 10. The alignable connector of claim 1, further comprising a connection formed between the second element and the rotor capable of passing electrical signals, optical signals or fluid while rotationally fixed.
 11. The alignable connector of claim 10, wherein the connection comprises a male connector disposed on either the second element or the rotor mateable with a female connector disposed on the other of the second element or the rotor.
 12. The alignable connector of claim 11, wherein the male connector is shorter than a protrusion, crenellation, or mule shoe rotationally fixing the second element with the rotor.
 13. The alignable connector of claim 10, wherein the connection is parallel with a rotational axis of the rotor.
 14. The alignable connector of claim 10, wherein the connection comprises an electrical stab connection comprising a wiper capable of cleaning the stab connection upon stabbing.
 15. The alignable connector of claim 1, further comprising a rotatable connection formed between the rotor and the stator capable of passing electrical signals, optical signals or fluid while the rotor is rotating with respect to the stator.
 16. The alignable connector of claim 15, wherein the rotor comprises a conductive ring or an inductive ring capable of passing electrical signals to a conductive ring or an inductive ring of the stator.
 17. The alignable connector of claim 16, wherein the rotor comprises at least three conductive rings or inductive rings each capable of passing a unique signal.
 18. The alignable connector of claim 15, wherein the rotatable connection comprises a reflective surface disposed on either the rotor or the stator capable of directing an optical signal.
 19. The alignable connector of claim 15, wherein the rotor comprises a groove capable of passing fluid to another groove of the stator.
 20. The alignable connector of claim 15, wherein the rotatable connection is disposed within a pressure vessel. 